Farm animals are far more aware and intelligent than we ever imagined and, despite having been bred as domestic slaves, they are individual beings in their own right. As such, they deserve our respect. And our help. Who will plead for them if we are silent? Thousands of people who say they ‘love’ animals sit down once or twice a day to enjoy the flesh of creatures who have been treated so with little respect and kindness just to make more meat.

Chimps are brutal, and it is so deliberate. The males go out and get near the boundary of their territory. And they walk very silently trying hard not to make any noise. They will climb into a tree and stare out over hostile territory for hours. They are waiting for the right opportunity. And then they attack.

I think anything is better than war. The extent to which one can negotiate with fanatics, I have no idea. I don't know.

In Tanzania, the chimps are isolated in a very tiny patch of forest. I flew over it 13 years ago and realized that, basically, all the trees had gone, that people all around the park are struggling to survive. It became very clear that there was no way to protect the chimps while the people were in this dire circumstance.

It's been proven by quite a few studies that plants are good for our psychological development. If you green an area, the rate of crime goes down. Torture victims begin to recover when they spend time outside in a garden with flowers. So we need them, in some deep psychological sense, which I don't suppose anybody really understands yet.

The chimpanzees taught me a lot about nonverbal communication. The big difference between them and us is that they don't have spoken language. Everything else is almost the same: Kissing, embracing, swaggering, shaking the fist.

You may not believe in evolution, and that is all right. How we humans came to be the way we are is far less important than how we should act now to get out of the mess we have made for ourselves.